Circuit breaker



Oct. l1, 1938. J. G. JACKSON v2,132,626

CIRCUIT BREAKER Filed April 1, 1956 2 Sheets-Sheet l l l l i f u mi U l Oct. 1l, 1938. J. GJAcKsoN CIRCUIT BREAKER Filed April l, 1936 2 Sheets-Sheet 2 v INVENTOR. JVI vG.' EclsazL BYy;

A TTORNE Y.

Patented Oct. 11, 1938 UNITED STATES PATENT OFFICE CIRCUIT BREAKER tion of Michigan Application Api-u 1, 193s, serial Na 12,034

11 claims. (ci. zoo-11s) I'his invention relates to apparatus for making and breaking electric circuits and more particularly to electric circuit. breakers automatically operable to break the circuit in response to a current overload and constitutes a modification of the circuit breaker described and claimed in applicants copending application, Serial No. 36,247, filed August 15, 1935.

One object of the present invention is to provide a method of feeding a plurality of electric circuits through a unitary sealable multi-circuit circuit breaker embodying a sealable enclosure with a plurality of individual circuit breaker mechanisms within the enclosure and having l5 electrically common current responsive elements.

Another object'of the present invention is to provide an automatic multi-circuit electric circuit breaker including a plurality of individual automatic electric circuit breaker mechanisms having electrically common current responsive elements.

Anotherobject of the Vpresent invention is to provide a multi-circuit circuit breaker having a plurality'of individual automatic electric circuit breaker mechanisms which include series connected bimetallic elements with the bimetallic elements provided with a common mounting means.

Another object of the present invention is to 3o provide an improved multi-circuit circuit breaker.

Another object of the present invention isto provide an improved supporting means for bimetallic elements in a circuit breaker.

35 Other objects and features of the invention will be readilyA` apparent to those skilled in the art from the following specification and appended drawings illustrating certain preferred embodiments of the invention in which:

40 Figure 1 is a front elevational view of'a circuit breaker assembly with the cover parts broken away to show the internal mechanism.

Figure 2 is a vertical sectional view taken on the line II-II of Figure 1.

45 Figure 3 is a partial View similar to Figure 2 showing the parts in diierent position.

In the assembly there is .shown an outer metallic enclosing box I having an openable cover 2. Within the box is hingedly supported 50 a strap 3 of generally U-shape, having the leg opposite the hinge closely embracing the cooperating side wall of the box and carrying a. stud 4 received within a slot in the side wall of the box to maintain the strap in its interior position.

u 'On the strap are disposed in juxtaposed relation two multi-circuit circuit breaker units 5 and 6 of identical form. These units embody generally cup-shaped' bases I having metallic covers 8 sealably secured thereto as by means of rivets 9.

'I'he individual circuit breaker mechanisms are 5 provided with operating handles II extending through the covers 8. In the juxtaposed assembly of Figure 1 the adjacent handles on the two units are joined together for common movement by means of an element I2 carrying portions dis- 10 posed in openings in the handles as more fully described and claimed in applicants copending application, Serial No. 114,021 led December 3, 1936, and constituting adivision of application Serial No. 72,035, iiled April l, 1936. It is noted l5 that in the assembly the exterior cover 2 has a central opening to permit access to the operating handles while the cover is in place and overlaps the covers 8 for the individual units as more particularly shown in Figures 2 and 3. 20

'I'he individual mechanisms for the breakers correspond in general to that disclosed in the first mentioned copending application and embody a iioating contact bar I3 having a notch I4 in its upper edge receiving the top edge of a 25 cooperating slot in one leg olf a rectilinearly movable member I5, generally U-shaped in cross section. The opposite leg of this element is considerably shorter than the bar engaging leg and constitutes a stop for the bar in its automatically tripped position. The element I5 is guided for rectilinear movement at right angles to the back of the base by means of suitable projections within the base as is more fully explained in the first mentioned copending application. The bar I3 is provided at the end adjacent the ends of the base with contact surface I 6 and at its opposite end with the latching surface I1 adapted to cooperate with a bimetallic element I8 having its free end connected to a mid point on the bar by means of a iiexible lead I9. Ledges 2| are provided on the ends of the exterior of the base and connectors 22 carrying contact surfaces on the ends disposed within the base interior are rigidly mounted on the ledges by spun over ends of metallic inserts 23. Terminal studs are provided threaded into the inserts 23. Fibre plates 2l are disposed at the ends oi' the base and are maintained in place by the overhanging portion of the covers 8 to sealably enclose the interior against access. A compression spring 25 is disposed between the bottom edge of the bar I3 and the back of the base The base is provided with anv elongated central Supporting wall 26 upon which is supported a 55 conducting plate 21 having integral corner extensions return bent to form spaced parallel portions 28 and intermediate connecting portions 29. To each of the connecting portions 29 is Welded or otherwise rigidly secured one end of the bimetallic latching elements IB. Adjusting studs 3| may be threaded into the parallel portions 28 l and bear against the plate 21, thus providing ving ends of the bimetallic elements.

'the latching tip of the bimetal.

means for varying the angle of the connecting portions 29 with respect to the plate and consequently for adjusting the position of the latch- A libre or other insulating piece 32 may be provided over the bimetallic mounting assembly to properly insulate it from the cover 8.

The interior portions of the handles I I are provided With cam surfaces 33 adapted to cooperate with the tops of the members I5 to eiect movement thereof to actuate the breaker mechanism. The handles are mounted for rotary movement upon shafts 35 disposed within recesses 36 in the side walls of the base. Relatively light springs 34 are provided to bias the operating handles for rotation toward the oi position, thus forcing the cam surfaces 33 against the members I5 and holding the members I5 within the notches I4 in the bars I3. These springs enable the handles to assume a definite on position as shown at the left in Figure 2.

The circuit breaker mechanism shown at the left in Figure 2 is in the on position with the stationary and movable contact surfaces engaged. To move the parts to the manual oi position the handle II is rotated counterclockwise to the dotted line position there shown, whereupon the parts will assume the position shown in reverse at the right in Figure 2. The cam surface 33 transforms the rotary movement of the handle into rectilinear movement of the element I5, whereupon the bar I3 is moved toward the back of the base. For the major part of this movement the bar I3 pivots about the engagement of its latching surface I1 with the bimetallic latch I8 until the contact carrying end of the bar engages the back of the base or other stop, whereupon the latching end of the bar is moved slightly beyond As the engagement between the camming surface and the member I5 is now substantially in line with the pivot point for the handle, it is seen that this constitutes a stable position which the parts will maintain. When the parts are in the on position, if a current overload should occur, the corresponding bimetal will ex or bend due to the heat generated therein and the free end of the bimetal will move out of engagement with the latching end of the bar I3. This permits the bar to rotate under the action of its biasing spring 25 into the position shown in Figure 3. This rotative motion is limited by the engagement of the bar with the shorter leg of the member I5. As the operating spring 25 is many times stronger than the handle biasing spring 34, release of the bar causes an upward movement of the member I5 which rotates the handle into the position shown in Figure 3 which corresponds to a position of the exterior part of the handle shown in dotted lines as a clockwise rotation of the handle shown at the left in Figure 2.

To reset the breaker mechanism after an automatic operation, the handle is rotated toward the off position whereupon the cam surface 33 moves the parts to the position shown in Figure 2 corresponding to the manual ofi position. Inthis movement the contact end of the bar I3 rst engages the back of the box or other stop and is then rotated about the engagement of notch I4 within the member I5 into the position shown at the right in Figure 2. To place the parts again in the on position the handle is rotated in the opposite direction whereupon the latchlng end of the bar engages with the bimetal, if it has in the meantime cooled sufficiently to assume its normal position, and the movable contact surface on the bar will engage with the stationary contact surface on the connector 22.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation Within the terms of the following claims:

What is claimed is:

1. In a multi-circuit, automatic electric circuit breaker, a common base, a plurality of electrically common bimetallic latching elements mounted on said base, a plurality of individual automatic electric circuit breaker mechanisms on said base including stationary and movable contacts and means for automatically moving the movable contact to a disengaged position upon movement of the corresponding bimetallic element, a cover sealably attached to said base to form a sealable enclosure for the circuit breaker, and circuit terminals readily accessible on the outside of the enclosure and connected to said stationary contacts.

2. In a multi-circuit, automatic electric circuit breaker, a common base, a plurality of individual circuit breaker mechanisms on said base including stationary and movable contacts, a member releasable to eiect movement of the movable contact and current responsive means for releasing said member, a cover sealably attached to said base to form a sealable enclosure for the circuit breaker, one terminal for each of said mechanisms being readily accessible on the exterior of the enclosure, the other terminals for said mechanisms being sealed within the enclosure and at least electrically connected together, said other terminals being connected to the corresponding.

current responsive means of the mechanisms.

3. In a multi-circuit, automatic electric circuit breaker, a common base, a plurality of individual circuit breaker mechanisms on said base including stationary and movable contacts, a member releasable to eiect movement of the movable contact and current responsive means for releasing said member, a cover sealably attached to said base to form fa sealable enclosure for the circuit breaker, one terminal for each of said mechanisms being readily accessible on` the exterior of the enclosure, the other terminals for said mechanisms comprising a cluster of electrically connected supporting means for the current responsive means of the mechanisms, said cluster being mounted within the sealable enclosure.

4. In a multi-circuit circuit breaker, a sealable enclosure, a plurality of individual automatic electric circuit breaker mechanisms within said enclosure including stationary and movable contacts, a member releasable to eiect movement of the movable contact and a seriesconnected, bimetallic element for releasing said member, one terminal for each of said mechanisms being readily accessible on the exterior of the enclosure, the other terminals for said mechanisms including a conducting element 2,132,626 carrying adjustable means for supporting the biable to eiect movement of the movable contact and a series connected bimetallic element for releasing said member, one terminal for each of said mechanisms being connected to its stationary contact and extending to and readily accessible at the exterior of the enclosure, the other terminals for said mechanisms being electrically common and inaccessible within the enclosure and connected to the bimetallic elements.

6. In a multi-circuit circuit breaker, an elongated base, a cluster of electrically connected bimetallic elements mounted substantially centrally of the base, stationary contacts mounted adjacent to the opposite ends of the base, a movable contact bar extending from a bimetallic element to each contact and carrying a contact surface adjacent to one end cooperating with said contact, said bar latching at its opposite end to a bimetallic element, and biasing means for each of said bars for moving them to a contact disengaged position when released by the bimetallic elements.

7. In a multi-circuit circuit breaker, an elongated base, a cluster of electrically connected bimetallic elements mounted substantially centrally of the base, stationary contacts mounted adjacent to the opposite ends of the base, a movable contact bar extending from a bimetallic element to each contact and carrying a contact surface adjacent to one end cooperating with said contact, said bar latching at its opposite end to a bimetallic element, biasing means for each of said bars for moving them to a contact disengaged position when released by the blmetallic elements, a coversealably secured to said base, and an exterior circuit terminal connected to each of said stationary contacts.

8. In a multi-circuit circuit breaker, an elongated sealable enclosure, electrically connected bimetallic elements mounted within and substantially midway between the ends of said enclosure, at least one circuit breaker mechanism mounted between the bimetallic elements and each end of the enclosure and including separable contacts and a member releasable by the corresponding element to cause separation of the contacts, and an external terminal for each of said mechanisms on the outside ends of said enclosure.

9. In an electric circuit breaker, supporting means for a bimetallic element comprising a conducting strap having a return bent portion, a bimetallic element rigidly secured at one end to said portion and an adjusting screw cooperating with said strap and return bent portion for changing the position of said element.

10. In an electric circuit breaker, supporting means for a bimetallic element comprising a main body portion having an integral portion in spaced relation thereto, a bimetallic element rigidly secured to the portion joining said rst mentioned portions, and an adjusting stud threaded in one of said iirst mentioned portions and bearing against the other of said portions to provide means for moving the bimetallic element. l

11. In an electric circuit breaker, supporting means for a bimetallic element comprising a conducting plate having a plurality of integral portions disposed in superposed, spaced relation, a bimetallic element integrally connected at one end to each ofthe portions joining said spaced portions to the plate, and adjusting screws threaded into said spaced portions and bearing against the plate for changing the positions of said elements.

JOHN G. JACKSON. 

